2D movement problem

Hi
I have a problem with moving around my character, i want to move the player relative to the change in the current Touches position, but this script does nothing, my character stand in one place. I’m working with unity remote on android.
using UnityEngine;
using System.Collections;

public class PlayerController : MonoBehaviour {
    public Vector3 start;
    public Vector3 dir;
    public Camera kamera;

    void Start ()
    {
	
	}
	
	void Update ()
    {
        
        if (Input.touchCount != 0) 
        {
            Touch erint = Input.GetTouch(0);
            switch (erint.phase)
            {
                case TouchPhase.Began:
                    start = kamera.ScreenToWorldPoint(erint.position);
                    break;
                case TouchPhase.Moved:
                    dir = start - kamera.ScreenToWorldPoint(erint.position);                    
                    this.transform.Translate(dir, Space.World);
                    break;
            }
        }
	}
}

Thanks for the help in advance.

Set value of Projection property of Camera component to Orthographic from Perspective.